c_g_dbus_connection_add_filter

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
uint function(GDBusConnection* connection, GDBusMessageFilterFunction filterFunction, void* userData, GDestroyNotify userDataFreeFunc) c_g_dbus_connection_add_filter;

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